As physicians require ever improved images, so too the development of the MRI-Systems has to keep pace if it is meet this demand. A few years ago a 1.0 Tesla (T) MRI System would be considered a very high magnetic field strength, today; this has more than doubled with 3.0T systems operating in the high end of the market. In the field of human medicine research, MRI-Systems with 4.0T or 9.4T are in use. Additionally, in the physical, chemical and biomedical research areas MRI-Systems of 21.0T are employed.

In practice this means that the critical field lines (e.g., 0.5 mT) move away from the ISO-center of the magnet and can often be outside of the RF Room; this phenomenon must be considered for each installation. Primarily, the Magnetic field from the MRI Scanner must not be disturbed, while at the same time ensuring that any residual Magnetic field outside the RF Room, will not have an affect on other persons or equipment.